The use of aqueous compositions for the surface treatment of metal, ceramic, glass, and plastic articles is well known. Additionally, cleaning, plating, and deposition of coatings on the surface of articles are known to be carried out in aqueous media. In both cases, a halocarbon solvent and a hydrophobic surfactant may be used to displace water from a water-laden surface.
A variety of solvent-surfactant drying compositions for water displacement have been utilized. For example, solvent-surfactant compositions based on 1,1,2trichlorotrifluoroethane (“CFC-113”) are known. However, environmental concerns are leading to a decline in the use of such CFC-based systems.
Applicants have come to recognize that it is generally not possible to predict whether a particular surfactant or group of surfactants will be fully acceptable for use with a given solvent or group of solvents, including hydrochlorofluorocarbons (“HCFC's”), hydrofluorocarbons (“HFC's”), hydrochlorofluoro-olefins (“HCFO's”) and hydrofluoro-olefins (“HFO's”) and hydrofluoroethers (“HFE's”) solvents suitable to replace CFC solvents. Moreover, many of the known surfactants cannot be dissolved in such solvents. Further, dry cleaning, drying, and water displacement require surfactants that, together with the chosen solvent, impart distinct, and a difficult to achieve set of properties to the cleaning compositions. For the removal of oil from machined parts, the surfactant will preferably aid in the removal of the soils that would otherwise only be sparingly soluble in such solvents. Additionally, water displacement requires a surfactant that does not cause the formation a stable emulsion with water.
Applicants have come to appreciate that halogenated olefin solvents in general, and chloro-fluoro-olefins in particular, present the additional difficulty of identifying combinations of such solvents and surfactants that not only possess the desired solvency and other properties, but which also exhibit an acceptable level of stability since olefins are generally understood to be reactive, especially in comparison to many previously used solvents.
Therefore, one must not only identify those surfactants soluble in the HCFC, HFC, HCFO, HFO, or HFE solvent selected, but also surfactants that also have the desired activity in the solvents and which exhibit acceptable levels of stability.